The first church in Rhuddlan was built around 1080. In 1301, a new church had to be built, as the older one had to be pulled down to make place for the castle, then erected. In the second half of the fifteenth century, the church was enlarged by a second aisle, and around 1500 a tower on its west side. The expansion probably took place as a result of damages to the building during the Welsh rebellion of Owain Glyndŵr at the beginning of the fifteenth century. In the nineteenth century, the church underwent several Victorian renovations, during which the appearance of the nave and the chancel were unified. The nave and presbytery of the 14th century started to act as a side aisle, and the aisle of the 15th century took over the functions of the main nave and the presbytery. In 1820, on the northern side of the church, Bodrhyddan’s Mausoleum was added.
The church was built as an aisleless building on a rectangular plan. Judging by the piscina preserved inside, the chancel was added a little later, but still in the fourteenth century. It it had a similar, but not identical, width to the nave and ended in the east with a straight wall. In the second half of the fifteenth century, on the north side, a new aisle was added in the English Perpendicular Gothic style and a four-sided tower of the same width adjoined it from the west. Both parts of the church had the same length, creating in the plan a strongly elongated rectangle, although the regularity of the layout could have been disturbed by a slightly narrower 14th century chancel. The outer elevations were reinforced with irregularly placed buttresses, including two in the south-west corner and two at the tower (one low and one high, stepped, reaching above the windows of the upper floor). Inside, the northern aisle was opened to the south with six arcades, and the entrance led from the south, through the 15th-century porch.
The church was heavily transformed in the 19th century, especially its original architectural details were replaced. Only in the northern wall of the presbytery, late-medieval windows from the turn of the 15th and 16th centuries have been preserved, and the entrance portal has been moved to the southern wall. On the south side there is also a 15th-century porch, however, it was rebuilt in the 19th century. Completely modern additions are the sacristy at the tower on the north-west side and the chapel (mausoleum) on the north-east side. The walls of the 14th-century chancel, whose walls were unified with the southern and northern aisles, were rebuilt firmly.
Salter M., The old parish churches of North Wales, Malvern 1993.
Website cpat.demon.co.uk, Church of St Mary, Rhuddlan.